In 1927, Ivan Pavlov experimented with his dog on the subject of psychological training--specifically conditional stimuli and response. He found that when he rang a bell each time before he fed his dog, the dog no longer salivated in response to the food, but to the bell.

A conditional response is when you're trained to respond to something such as Pavlov's bell, as opposed to using simply your reflexes.

In 1927 Ivan Pavlov discovered "respondent conditioning" when pairing a sound or action with a positive experience. he discovered that if he rang a bell every time he fed his dog. after many times the dog started to salivate at the sound of the bell in anticipation of receiving food.

clicker training turns any dog into Pavlov's dog they get excited in anticipation of receiving a treat when the clicker is heard.